The effect of different types of ankle foot orthoses on balance and stability

Ankle-foot orthoses (AFOs) have been shown to negatively affect dynamic balance, while having little or positive impact on static balance. The cost of carbon composite AFOs (cAFOs) is higher than traditional polypropylene AFOs (pAFOs), yet there is limited research comparing the two. This study investigated the effect of using carbon and polypropylene AFOs on static and dynamic balance. We hypothesized that postural sway would be reduced when wearing the cAFO (which has an anterior shell) compared to the pAFO. Seventeen healthy college-aged students first completed quiet-standing trials of the Modified Test of Sensory Interaction on Balance on a force-measuring platform with (1) Eyes Open, (2) Eyes Closed, (3) Eyes Open on Memory Foam, (4) Eyes Closed on Memory Foam. Two trials were recorded for each of three AFO conditions: noAFO, cAFO, and pAFO. Participants then completed three Sit-to-Stand trials for each AFO condition. A number of traditional postural sway measures were calculated. Differences between conditions were determined by Paired-Samples T-Tests (p\u3c0.05). The use of either type of AFO compared to the noAFO condition resulted in decreased sway across 3 out of 4 flat plate conditions. The pAFO elicited greater sway in all conditions than the cAFO. Using the cAFO compared to noAFO resulted in significantly increased sway on the Memory Foam with Eyes Open, suggesting that individuals who may regularly encounter challenging terrain (sand, hiking paths, etc.) may not benefit from a cAFO. Both the cAFO and pAFO elicited significantly larger sway in Sit-to-Stand trials compared to noAFO, suggesting that AFO users may have difficulty performing this routine task, likely due to restricted ankle function. Our work may help clinicians because the choice of AFO is condition-dependent. The use of an AFO generally provides increased stability under normal conditions, and the cAFO provides more stability than the pAFO.https://ecommons.udayton.edu/stander_posters/3762/thumbnail.jp